Temporarily add a public modPow method to _Bigint class.

Temporarily add a public modPow method to _Bigint class.

R=srdjan@google.com

Committed: https://code.google.com/p/dart/source/detail?r=40271

[regis, 2014-09-12 23:05:12]

regis@google.com changed reviewers:
+ srdjan@google.com

[regis, 2014-09-12 23:05:13]

I have also split the _am method into _am and _amc, since different assembly
code will be required in the intrinsics.

Interestingly, _am is not showing up very high on the cpu profile. _am in Tom
Wu's version was showing up very high and intrinsifying it made a huge
difference (factor 2 speedup).

This will not work as easily here. We will need to intrinsify _reduce in
addition of intrinsifying _am and _amc.

[regis, 2014-09-15 16:52:15]

On 2014/09/12 23:05:13, regis wrote:
> I have also split the _am method into _am and _amc, since different assembly
> code will be required in the intrinsics.
> 
> Interestingly, _am is not showing up very high on the cpu profile. _am in Tom
> Wu's version was showing up very high and intrinsifying it made a huge
> difference (factor 2 speedup).
> 
> This will not work as easily here. We will need to intrinsify _reduce in
> addition of intrinsifying _am and _amc.

Never mind my comment about _am not showing up very high on the cpu profile. It
does, as well as _amc. I simply forgot to pass the --no_use_inlining flag while
profiling. So that is good news.

[srdjan, 2014-09-15 18:10:52]

lgtm

https://codereview.chromium.org/567093002/diff/1/runtime/lib/bigint.dart
File runtime/lib/bigint.dart (right):

https://codereview.chromium.org/567093002/diff/1/runtime/lib/bigint.dart#newc...
runtime/lib/bigint.dart:1096: // New methods to support crypto.
Maybe remove this comment?

https://codereview.chromium.org/567093002/diff/1/runtime/lib/bigint.dart#newc...
runtime/lib/bigint.dart:1125: int modPow(int e, int m) {
Maybe in a later CL: You may also implement a modPow in IntegerImplementation in
case receiver is not Bigint.

[regis, 2014-09-15 19:29:19]

Committed patchset #2 (id:20001) manually as r40271 (presubmit successful).

[regis, 2014-09-15 19:29:31]

Thanks!

https://codereview.chromium.org/567093002/diff/1/runtime/lib/bigint.dart
File runtime/lib/bigint.dart (right):

https://codereview.chromium.org/567093002/diff/1/runtime/lib/bigint.dart#newc...
runtime/lib/bigint.dart:1096: // New methods to support crypto.
On 2014/09/15 18:10:52, srdjan wrote:
> Maybe remove this comment?

Done.

https://codereview.chromium.org/567093002/diff/1/runtime/lib/bigint.dart#newc...
runtime/lib/bigint.dart:1125: int modPow(int e, int m) {
On 2014/09/15 18:10:52, srdjan wrote:
> Maybe in a later CL: You may also implement a modPow in IntegerImplementation
in
> case receiver is not Bigint.

Will do.